What should be paid attention to when printing in color?

What should we pay attention to when doing color printing? Color printing is not just a simple normal 4-color printing. There are many foreign customers who often appear in their books and periodicals with various spot colors. Especially for a brand Red color, this color is the most difficult to adjust, and many customers will use spot color, or after printing water oil, increase the amount of black ink on the basis of color, will not change the hue of the mixed color, and reduce the The lightness of the color also reduces the chroma. Generally speaking, in the four-color printing technology, the color of the picture is the most important issue. Therefore, we must pay attention to the color problem in the four-color printing. Special attention should be paid to this color design

1. Empty

If there is a line of blue characters pressed on the yellow bottom plate, then on the yellow plate of the film, the position of the blue characters must be empty. And vice versa for the blue version. Otherwise, if the blue thing is directly printed on the yellow, the color will change, and the original blue characters will become green.

2. Overprinting

If there is a line of black characters pressed on a red substrate, then on the red version of the film, the position where the black characters are located should not be hollowed out. Because black can suppress any color, if the black content is hollowed out, especially for some small characters, a slight error in printing will lead to white edges, and the contrast between black and white is large, which is easy to see. the

3. Four-color black

This is also a more common problem. Before output, it must be checked whether the black characters in the publication file, especially the small characters, are only on the blackboard and should not appear on other three-color versions. If so, the quality of the printed product will be compromised. When the RGB graphics are converted to CMYK graphics, the black text will definitely become four-color black. Unless otherwise specified, it must be processed before the film can be output. the

4. The picture is in RGB mode

When an image in RGB mode is output, the RIP system will generally automatically convert it to CMYK mode for output. However, its color quality will be greatly reduced, and the printed product will be light in color, not bright, and the effect will be very bad. It is best to convert the picture to CMYK mode in Photoshop. If it is a scanned manuscript, it must go through the process of color correction before the picture can be used. Many friends don't care about the RGB and CMYK formats when making files in PS.